Intrinsic and extrinsic dielectric contributions to the electrical properties in CaZrO3-doped KNN-based electrical/optical multifunctional ceramics

• Published in: Journal of materials science 2020-05, Vol.55 (14), p.5741-5749
• Main Authors: Shi, Wenming, Du, Juan, Zhai, Yuzhi, Chen, Chong, Wei, Yanyan, Li, Wei, Hao, Jigong, Fu, Peng
• Format: Article
• Language: English
• Subjects: Calcium zirconate; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Dielectric properties; Domain walls; Electrical properties; Ferroelectric materials; Ferroelectricity; Grain size; Lead free; Materials Science; Optical properties; Phase transitions; Photoluminescence; Piezoelectric ceramics; Piezoelectricity; Polymer Sciences; Solid Mechanics; Solid phases; Transition temperature
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-020-04444-6

In this work, (0.9985 −  x )(K 0.49 Na 0.49 Li 0.02 )(Nb 0.8 Ta 0.2 )O 3 –0.0015Ho 2 O 3 – x mol%CaZrO 3 (KNLNT–Ho– x CZ) lead-free piezoelectric ceramics were prepared by traditional solid-state reaction method. Dielectric, ferroelectric, photoluminescence properties and Rayleigh behavior were studied. The addition of CaZrO 3 caused the orthorhombic to tetragonal phase transition temperature T O–T to decrease, and when x  ≥ 0.02, the phase structure was converted from orthorhombic–tetragonal coexistence phases to pseudo-cubic one. With the addition of CaZrO 3 , grain size showed a decreasing trend. Under a wavelength of 453 nm excitation, a strong green emission (~ 551 nm) was observed, corresponding to the transitions of 5 S 2  →  5 I 8 . Furthermore, Rayleigh analysis showed that doping CaZrO 3 reduced the grain size and clamped the domains, making the domain wall movement and domain switching difficult, thus weakening the extrinsic contribution of ceramics.